The Connecticut shoreline was briefly under a tsunami warning before the National Weather Service disclosed the alert had been sent by mistake during a routine monthly test.

The Weather Service's office in New York sent the warning Thursday morning to its radio and emergency alert systems, which resulted in the alert being mentioned on local broadcasts and Twitter posts. The warning was for all four coastal counties and part of Long Island Sound.

The Weather Service later issued a statement saying there was no real tsunami threat and the warning was sent inadvertently during a routine monthly test by the service's National Tsunami Warning Center in Alaska.

The Connecticut Broadcasters Association says the alert ran on several Connecticut stations.